This Core will serve as the laboratory component for the program project, a unit that will serve all three projects through a combination of immunologic and genetic determinations. Dr. She (core leader) and Dr. McIndoe (co-core leader) will provide scientific management of this core. The goals of this core will be: 1. To measure autoantibodies commonly associated with or have predictive value for type 1 diabetes: GADA, IA2-A for human and IAA for mice. 2. To provide information ascribing genetic susceptibility by HLA-DR and -DR genotyping. 3. To measure gene expression levels for immune-related genes using the high throughput cDNA microarray technologi